package com.unify.python.http;

import com.alibaba.fastjson.JSONObject;
import com.unify.python.config.PythonConfig;
import org.apache.http.*;
import org.apache.http.client.HttpClient;
import org.apache.http.client.HttpRequestRetryHandler;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.conn.routing.HttpRoute;

import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HttpContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import sun.misc.IOUtils;

import javax.net.ssl.SSLException;
import javax.net.ssl.SSLHandshakeException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.UnsupportedEncodingException;
import java.net.UnknownHostException;
import java.util.*;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

/**
 * @Date: 2018/12/18 23:32
 * @Auther: wchen
 * @Version: 1.0.0
 * @Description:
 */
public class HttpConnectionPoolClient {
    private static Logger logger = LoggerFactory.getLogger(HttpConnectionPoolClient.class);

    private static PythonConfig config = new PythonConfig();
    private static CloseableHttpClient httpClient; // 发送请求的客户端单例
    private static PoolingHttpClientConnectionManager manager; //连接池管理类
    private static ScheduledExecutorService monitorExecutor;

    private final static Object syncLock = new Object(); // 相当于线程锁,用于线程安全

    private HttpConnectionPoolClient(){}

    /**
     * 对http请求进行基本设置
     * @param httpRequestBase http请求
     */
    private static void setRequestConfig(HttpRequestBase httpRequestBase){
        RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(PythonConfig.connectionTimeout)
                .setConnectTimeout(PythonConfig.connectionTimeout)
                .setSocketTimeout(PythonConfig.socketTimeout)
                .build();

        httpRequestBase.setConfig(requestConfig);
    }


    /**
     * 获取httpClient
     * @return
     */
    public static CloseableHttpClient getHttpClient(){
//        String hostName = url.split("/")[2];
//        System.out.println(hostName);
//        int port = 80;
//        if (hostName.contains(":")){
//            String[] args = hostName.split(":");
//            hostName = args[0];
//            port = Integer.parseInt(args[1]);
//        }

        if (httpClient == null){
            //多线程下多个线程同时调用getHttpClient容易导致重复创建httpClient对象的问题,所以加上了同步锁
            synchronized (syncLock){
                if (httpClient == null){
                    httpClient = createHttpClient();
                    //开启监控线程,对异常和空闲线程进行关闭
                    monitorExecutor = Executors.newScheduledThreadPool(1);
                    monitorExecutor.scheduleAtFixedRate(new TimerTask() {
                        @Override
                        public void run() {
                            //关闭异常连接
                            manager.closeExpiredConnections();
                            //关闭5s空闲的连接
                            manager.closeIdleConnections(PythonConfig.httpIdlTimeout, TimeUnit.SECONDS);
                            logger.info("close expired and idle for over 5s connection");
                        }
                    }, PythonConfig.httpInitDelay, PythonConfig.httpMonitorInterval, TimeUnit.SECONDS);
                }
            }
        }
        return httpClient;

//        return HttpClients.createDefault();
    }

    /**
     * 构建httpClient
     * @return
     */
    private static CloseableHttpClient createHttpClient(){
        ConnectionSocketFactory plainSocketFactory = PlainConnectionSocketFactory.getSocketFactory();
        LayeredConnectionSocketFactory sslSocketFactory = SSLConnectionSocketFactory.getSocketFactory();
        Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory> create()
                .register("http", plainSocketFactory)
                .register("https", sslSocketFactory)
                .build();

        manager = new PoolingHttpClientConnectionManager(registry);
        //设置连接参数
        manager.setMaxTotal(PythonConfig.maxConn); // 最大连接数
        manager.setDefaultMaxPerRoute(PythonConfig.defaultRoute); // 默认最大连接数

//        HttpHost httpHost = new HttpHost(host, port);
//        manager.setMaxPerRoute(new HttpRoute(httpHost), config.maxPreRoute);

        //重试策略
        HttpRequestRetryHandler handler = new HttpRequestRetryHandler() {
            @Override
            public boolean retryRequest(IOException e, int i, HttpContext httpContext) {
                if (i > PythonConfig.sysHttpConnRetry){
                    //重试超过3次,放弃请求
                    logger.error("retry has more than 3 time, give up request");
                    return false;
                }
                if (e instanceof NoHttpResponseException){
                    //服务器没有响应,可能是服务器断开了连接,应该重试
                    logger.error("receive no response from server, retry");
                    return true;
                }
                if (e instanceof SSLHandshakeException){
                    // SSL握手异常
                    logger.error("SSL hand shake exception");
                    return false;
                }
                if (e instanceof InterruptedIOException){
                    //超时
                    logger.error("InterruptedIOException");
                    return false;
                }
                if (e instanceof UnknownHostException){
                    // 服务器不可达
                    logger.error("server host unknown");
                    return false;
                }
                if (e instanceof ConnectTimeoutException){
                    // 连接超时
                    logger.error("Connection Time out");
                    return false;
                }
                if (e instanceof SSLException){
                    logger.error("SSLException");
                    return false;
                }

                HttpClientContext context = HttpClientContext.adapt(httpContext);
                HttpRequest request = context.getRequest();
                if (!(request instanceof HttpEntityEnclosingRequest)){
                    //如果请求不是关闭连接的请求
                    return true;
                }
                return false;
            }
        };

        CloseableHttpClient client = HttpClients.custom()
                .setConnectionManager(manager)
                .setRetryHandler(handler)
                .build();
        return client;
    }



    /**
     * 关闭连接池
     */
    public static void closeConnectionPool(){
        try {
            httpClient.close();
            manager.close();
            monitorExecutor.shutdown();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}
